Tool for holding abrasive media



Sept. 26, 1950 R. c. HARRINGTON, JR 3,

TOOL FOR nowmc ABRASIVE MEDIA Fglled Jan. 21, 1949 2 Sheets-Sheet 1 INVENTOR TOOL FOR HOLDING ABRASIVE MEDIA Filed Jan. 21, 1949 2 Sheets-Sheet 2- I Gg I INVENTOR jig/z jgm/J flaw/V Patented Sept. 26,

UNITED STATES PATENT OFFICE 2,523,697 TOOL FOR HOLDING ABRASIVE MEDIA Robert C. Harrington, Jr.,.Kingsport, Tenn.

Application January 21, 1949, Serial N 0. 71,831

Claims. 1

This invention relates to a tool of the type frequently referred to in the art as a sand paper holder. More particularly, however, the present invention is concerned with an improved device comprising a hand tool contour sander.

Many types of sand paper holders have been described in the prior art. The earlier and most common type appears to be of a block construction more or less adapted to holding a flat sheet of abrasive or polishing material for application to a flat surface. In many instances, however, it is desirable to sand or polish concave or convex areas or surfaces having other special surface configurations. Hand finishing tools have been suggested having replaceableparts whichcorrespondto prismatic designs or the like over which the sand paper may be placed.

However, known constructions have, in gensander which is, of. courseynot too comfortable or convenient for best working conditions. Such block sanders are fairly complicated to construct and in some instances do not too securely or conveniently hold the sand paper.

The invention described hereinafter is an improved device of the class described and specifi cally a simpler and more versatile tool for holding abrasive or polishing sheet media as will be apparent as the description proceeds.

This invention has for one object to provide a tool forholding-abrasive or. polishing media in the form of sheets which is more. versatile. of operation than similar devices but yet is simpler and less expensive to construct. .A specific object is to provide an improved hand. tool contour sander which is adaptableto, working upon a variety of differently formed surfaces. Another object is to provide a tool of the class. described in which a plurality of different insert formsmay be readily interchanged. Afurther object is to provide a hand contour sander which may be used with sheets of sand paper, emery cloth, crocus cloth, or other abrading or polishing media in the form in which they are readily available ,in

hardware stores, for instance. Another object is to provide a simple'and relatively inexpensive method for-c-onstructing'the aforesaid tool.

Other objects will appear hereinafter. In the accompanying drawings,

Figure 1 is an elevational view in partial section, illustrating the manner in which the various elements of my improved sander are assembled, the devic being in its unloaded condition, that is, without the insertion of the abrasive sheet material.

Figure 2 is an elevational view, similar to Figure 1, and showing the manner in which the abrasive sheet is clamped in the frame member in operative position.

Figure 3 is a sectional view taken on line 3-3 of Figure 1 and showing in detail the magazine for holding the abrasive sheet material, the sheet clamping or locking element and one of the interchangeable form members around which the abrasive sheet material is carried and held, in operation.

Figure 4 is a sectional view taken on line 44 of Figure 2 in all respects similar to Figure 3, except that in this view the abrasive sheet material has been loaded into'the device and is shown proved sander of my invention.

Figure 6 is a fragmentary elevational view showing-the lowerpart of the frame member including'the element which holds the form member about whichthe abrasive sheet is wrapped in place.

Figure? is an elevational View illustrating one type of form and its internal slot which cooperates with the holding member illustrated in Figure 6.

Figure 8 is a fragmentary elevational view, in partial section, illustrating the manner in which the form member in Figure 7 co-acts with the holding member of Figure 6 and also illustrating one means whereby endwise movement of the form member in relation to the holding member is prevented.

Figure 9 is a cross-sectional view taken on the line 9-9 of Figure 7.

Figure 10 is a fragmentary view illustrating one form of locking bar for locking the abrasive sheet in place.

Figure 11 is a fragmentary cross-sectional view taken on the line ll-ll of Figure 10 illustrating the manner in which the locking bar may be formed from the frame member itself as a bent over'or'rolled down edge or portion thereof.

'Figure 12 is an elevational view showing the general shape of the form member as it appears when examined at right angles to the frame mem- 5 her.

Figures 13, 14, 15, 16, 17, 18 and 19 show typical contours of the form member which may be employed in accordance with my invention.

Referring to Figure 1, my improved tool is comprised of an over-all frame 2| which is provided with handles 3| and 32. It will be noted that the frame is of such a construction that it can be grasped by one hand at the top part of the frame or by both hands at 3| and 32. That is, the handles 3| and 32 may be of such angular design as lends itself to readily grasping and holding in the hands.

The lower portion of the frame is provided with a locking bar 28 or a rolled down member 34 (see Figures 8, and 11) of circular or similar shape over which the abrasive sheet may not only be conveniently drawn but may be locked against.

The various parts described above can be quickly and economically produced merely through stamping. The member 34, just referred to, asindicated, lends itself to formation by folding over and down a portion of the out out part in making the frame. I

Mounted adjacent to this locking bar 28 (or member 34, if this construction is employed) is a roll 22 (see Figures 3 and 4) which revolves on an axle 24. The roll may be knurled or otherwise roughened on its surface to increase the friction between itself and the flexible abrasive or polishing sheet 33. This roll is further provided with a slot 23 along its axis into which one end of the abrasive sheet 33 may be inserted in order that it may be securely held.

Mounted between the locking bar and the roll 22 is the clamping bar 2'! (see Figures 1 and 2) which cooperates with the locking bar and the roll to tighten and securely hold the sheet 33 in place on the tool. This clamping bar is held in place by' means of set screws 25 which are used to' tighten or loosen the clamping bar. Further, it can be seen that these three members cooperate in an unusual way to tighten and securely hold the sheet 33. Reference to Figure 4 which as already indicated is a cross section through 44 of Figure 2 shows a sheet of the flexible abrasive media inplace on the tool. After the flexible sheet'33 has been slipped under the clamping bar 27, the wing nuts 25 are tightened. Now since the holes provided for the bolts 26 in the clamping bar are oversize, the clamping [bar first bears against the roll 22 which action serves to hold the sheet abrasive on the roll in place, and firmly locks the loose end. As the wing-nuts are further tightened, the clamping bar pivots and is forced inward against the sheet abrasive which is now securely held at both ends. Finally, when the sheet abrasive is tight, the clamping bar bears against the circular member 28 or the member 34, as the case may be and holds the sheet abrasive firmly and tightly in place.

When a new surface of the abrasive sheet is desired, it is only necessary to loosen the set screws 25, pull the loose end of the sheet abrasive until enough unrolls from the magazine, or roll 22 topresent a fresh surface around the outside of the interchangeable form 29, and again tighten theset screws. Such an arrangement obviously permits great economy in the use of the flexible abrasive media.

As just referred to, mounted below these previously described members is the interchangeable form 29. This form, of any desired configuration, isg'rooved to accept the lower portion of the frame and is furtherprovided with a hole or slot to' accept the holding lug 30. In use, the inter- 4 changeable form is held securely against the frame of the tool by the tightened flexible sheet, and the lug on the frame cooperates with the slot or hole in the interchangeable form to prevent lateral motion of the interchangeable form.

Referring now to some of the variations that may be made in the construction of my invention Figure 5 shows an alternate shape for the upper part of the frame. In this design, the middle portion of the frame is curved to better fit the hand and is provided with hand grips, which are riveted to the frame.

Figure 6 shows an alternate design for the lower portion of the frame which is simple in design and which holds the interchangeable form securely. The lower portion here is given some simple curved shape, the shape which would correspond'to the curvature of a circular saw blade, for example. Consequently, the interchangeable form as shown in Figure '7 could be grooved by a circular saw, and would be ready to fit in place on the frame 2 1. Thus, when the flexible sheet abrasive media is tightened around an interchangeable form so slotted as to fit such a frame, it would be securely held in place.

Figure 8 shows still another means of holding tion of the cut-out part of the frame. Figure 11is a cross-section view along l l--! I of Figure 10 and shows the design of this circular member in detail.

Figure 12 is a side view of a typical interchangeable form and shows the position of the slot cut to accommodate the lower portion of the frame together with the'hole which accepts the-l holding lug 30 of the frame'member.

Figures 13, 14, 15, 16, 17,18 and 19 are end views of several of the interchangeable forms which may be used with thisimprove'd tool.

The many interchangeable forms which may be used with this improved toolmake it quite versatile. With various shaped forms, molding and furniture may be finished and many contours may be finely polished which cannot be polished with either the conventional type of hand sander or electric sander. A further importrant use to which this tool is well adapted is the refinishing of gun .stoclgs. For instance, an interchangeable form of the desired radius and with a cross section such as is shown in Figure 9' lends itself to the speedy and expert finishing of barrel grooves in stocks. This is particularly important since no sanders are available at this time which can do this job.

It is further to be understood that a' cushioning material such as felt may be placed between the interchangeable form and the flexible sheet abrasive media if sucha soft base is desired. I

Themanufacture of my tool as well as the manner of using the finished tool are apparent from the preceding description. However, a further understanding of the utility of my device will behad from-the following example of its operation wherein a sheet of sand paper is inserted and a special form attached so'that the device can be used to sand molding, barrel grooves in gun and the magazine rotated so that most of the flexible'sheet is wound on it: Next, the" desired interchangeable form is fitted on the bottom of the frame, and the-flexible sheet passed around the form. The freeend of-the flexible sheet is then passed over the locking bar 28, under the clamping'bar 21, and over the magazine 22. The wing nuts '25 are then tightened, and the clamping bar 21 performs its function in a unique manner. Asthe clamping bar is tightened, it first presses against the magazine, and the freeend of the flexible sheet abrasive. This action securely holds one end of thefle'xible sheet abrasive. At thesa me time, the'free end of the sheet abrasive is tightly held between the magazine and the clamping bar. At this point, the flexible sheet abrasive is held at its twoends. Since the holes in theclamping bar are larger in diameter than the'bolts 26 as'already mentionedpa nd since one side of theclamping bar-214s held against further movement by themagazine 22, further tightening of thewing nuts causes the clamping bar to rock or pivotfabout, the magazine as a pivot. This slight rotation serves to draw the flexible sheet 3'3 abrasive down-between the magazine 22 and the locking bar 21 thus causing the flexible sheet to become taut. Further tightening of the wing nuts causes the rotating clamping bar to finally press the flexible sheet abrasive between the' cla'mping bar andthe locking bar. At the same time, this tightening of the flexible sheet abrasive 33. holds the interchangeable form 29, etc. securely t o theframe while the lug or other of the'means described prevents the interchangeable form 29, etc.- from sliding out of position while the sander-is-being used.

At this point, the sander-is ready for use, and depending upon the shape of-the interchangeable form, an article having "contours corresponding to the form selected may be abraded or polished.

When the article undergoing sanding requires a greatTd-jalpf abrading or polishing, the handle like protr'usibns 3i and 32"are very convenient since they are curved to permit a heavy, yet sensitive pressure, and accurate guiding. On the other hand, the frame may be grasped-by one hand about the middle of its upper portion. Such an arrangement permits the article to be held by one hand and sanded with the other, and the tool thus has great versatility.

When the surface of the flexible sheet abrasive under the interchangeable form has become worn, it may be renewed by loosening the wing nuts 25 and pulling on the free end of the sheet until a new surface is presented under the interchangeable form. At this point, the wing nuts are tightened, and the sander is again ready for use.

Further, if it is desired to interchange forms,

the wing nuts 25 are loosened, the interchange- 6. tightened; Thetool is now again ready for use.

This hand contour tool has many advantages over those of the prior art, prominant among which are the facts that this improved sander can use sheets of'flexible abrasive or polishing media such as sand paper or emery cloth which are readily obtainable whereas other sanders require special rolls of sheet abrasive generally diflicult to acquire. The various interchangeable forms can be easily made by anyone with reasonable familiarity withtools, whereas the sanders described in the prior art have forms which are difficult to construct. Further, the frame is characterized by maximum utility in that the handle sheet,- and is, therefore, easier to grasp.

While in the above description of the operation I have specifically referred to the use of an abrasive paper, it'will be understood that this is merely illustrative and polishing fabric or' any other conventional flexible abrasive media may be used in my device. Likewise, in the above description while I have otherwise referred to specific construction for illustration, this construction may be varied, for example, as described in the various alternate views. Hence I do not wish to be restricted except insofar as is necessitated by the prior art, and the spiritof the appended'claims,

Iclaimr n l. A hand contour sander comprising in combination, a substantially rectangular unitary and rigid frame composed of side members and upper and lower end members and adapted to be grasped bythe upper end-member, a cylindrical magazine member rotatablyjmounted on the side members of the frame adjacent the lower end thereof and adapted to hold a length of abrasive sheet material,' a locking barfixedly attached to the, lower end member in parallelism with the magazine member and spaced therefrom, an adjustable clamping'bar adap-ted'both to bemoved away from and to be brought into surface contact with both thefmagazine member and the'locki'ng bar to permit" of insertion and ,of clamping in place.

ofthefabrasivefsheet material, an interchangeable rigid form, member apertured to receive the lowerjendmmembfer of the frame and adjustable means to move the, clampingbar into and out of clamping contact with the abrasive sheet material and the magazine member and the locking bar.

2. A hand contour sander comprising in combination, a substantially rectangular unitary and rigid frame composed of side members and upper and lower end members and adapted to be grasped by the upper end member, a cylindrical magazine member rotatably mounted on the side members of the frame adjacent the lower end thereof and adapted to hold a length of abrasive sheet material, a locking bar fixedly attached to the lower end member in parallelism with the magazine member and spaced therefrom, said locking bar consisting of a rolled down portion of the lower end member, an adjustable clamping bar adapted both to be moved away from and to be brought into surface contact with both the magazine member and the locking bar to permit of insertion and of clamping in place of the abrasive sheet material, aninterchangeable rigid form member apertured to receive the lower end member of the frame and adjustable means to move the clamping bar into and out of clamping contact with the abrasive sheet material and the magazine member and the locking bar.

3. A hand contour sander comprising in combination, a substantially rectangular unitary and rigid frame composed of side members and upper andlower end members, said upper end member being projected beyond the respective side memhere in the form of handles adapted to be grasped by an operator, a cylindrical magazine member rotatably mounted on the side members of the frame adjacent the lower end thereof and adapted to hold a. length of abrasive sheet ma terial, a locking bar fixedly attached to the lower end member in parallelism with the magazine member and spaced therefrom, an adjustable clamping bar adapted both to be moved away from and to be brought into surface contact with both the magazine member and the locking bar to permit of insertion of and of clamping in place of the abrasive sheet material, an interchangeable rigid form member apertured to receive the lower end member of the frame and adjustable means to move the clamping bar into and out of clamping contact with the abrasive sheet material and the magazine member and the locking bar.

4. .A hand contour sander comprising in combination, a substantially rectangular unitary and rigid frame composed of side members and upper and lower end members and adapted to be grasped by the upper end member, a cylindrical magazine member rotatably mounted on the side members of the frame adjacent the lower end thereof and adapted to hold a length of abrasive sheet material, a locking bar fixedly attached to the lower end member in lparal lelism with the magazine member and spaced therefrom, an adjustable clamping bar adapted both to be moved away from and to be brought into surface contact with both the magazine member and the locking bar to permit of insertion and of clamping in place of the abrasive sheet material, an interchangeable rigid form member apertured to receive the lower ,end member of the frame, a sheet of abrasive material wrapped around the magazine member and around the form,member andheld in clamped position between the clamping bar and the magazine member and locking bar, respectively, by adjustable means, permitting movement of said clamping bar toward and away from contact with the abrasive sheet material and the magazine member and locking bar.

5. A hand contour sander comprisin in combination, a substantially rectangular unitary and rigid frame composed of side members and upper and lower end members and adapted to be grasped by the upper end member, a cylindrical magazine member rotatably mounted on the side members of the frame adjacent the lower end thereof and adapted to hold a length of abrasive sheet material, a locking bar fixedly attached to the lower end member in parallelism with the magazine member and spaced therefrom, an adjustable clamping bar adapted both to be moved away from and to be brought into surface contact with both the magazine member and the locking bar to permit of insertion and of clamping in place of the abrasive sheet material, an interchangeable rigid form member apertured to receive the lower end member of the frame, a sheet of abrasive material wrapped around the magazine member and around the form member and held in clamped position between the clamping bar and the magazine member and locking bar, respectively, by adjustable means, said adjustable means comprisin threaded studs fixed to the side members and projecting through oversized apertures in the clamping bar, each of said studs being provided with adjusting nuts for moving said clamping bar toward and permitting its movement away from the abrasive sheet material and the magazine member and locking bar.

ROBERT C. HARRINGTON, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

